Ia type diamond color quick grading method based on spectrum

Abstract

The invention discloses an Ia type diamond color quick grading method based on a spectrum. The Ia type diamond color quick grading method based on the spectrum comprises that balanced compound light is emitted on a to-be detected diamond, and the compound light which is reflected through the to-be detected diamond is collected through an integrating sphere. After the light collected by the integrating sphere is split, a charge coupled device (CCD) detector is used for detecting so as to obtain a reflectance spectrum of the to-be detected diamond. After the reflectance spectrum of the to-be detected diamond is uniformized, a nitrogen absorption band is selected from the uniformized reflectance spectrum, and then the area of the nitrogen absorption band is calculated. Compared the area of the nitrogen absorption band with a standard threshold value file, the color of the to-be detected diamond is graded. According to the Ia type diamond color quick grading method based on the spectrum, the nitrogen absorption band is selected from the reflectance spectrum of the collected to-be detected diamond and the area of the nitrogen absorption band is calculated, then the area of the nitrogen absorption band is compared with the standard threshold value file, and so that the grading of the color of the diamond is achieved. The Ia type diamond color quick grading method based on the spectrum is simple in operation, quick and accurate in testing, high in consistency and capable of being widely used in the jewelry identification industry.

Description

technical field [0001] The invention relates to the field of jewelry identification, in particular to a method for quickly grading the color of type Ia diamonds based on spectrum. Background technique [0002] The chemical composition of diamond is carbon (C) element, and its crystal structure is a tetrahedron composed of 4 carbon atoms. Pure diamonds are colorless and transparent, but most natural diamonds contain trace amounts of impurity elements. According to analysis, the mass fraction of C in diamonds can reach 99.95%, and its secondary components include impurities such as N, B, and H. Diamonds are divided into two types based on the presence or absence of significant nitrogen, those containing nitrogen are referred to as type I diamonds, and those that do not contain appreciable amounts of nitrogen are referred to as type II diamonds. [0003] When diamonds are first formed, the nitrogen element in the crystal exists in the discrete state of single atoms. Under th...

AI Technical Summary

Problems solved by technology

However, the method of human eye observation and comparison not only takes a long time, but also reduces the accuracy of color grade judgment due to factors such as light source, background tone, diamond size, cut, and naked eye's ability to distinguish colors. Consistency in Color Grading

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